Air valve



Jan; 18,1927. 1, ,613

M. G. HUBBARD AIR VALVE Filed March 16, 1925 INVENTOR ATTORNEY Patented Jan. 18, 1927.

so STATES PATENT tries.

MOSES G'r. HUBBARD, OF CHA'IHAM, NEW JERSEY.

AIR VALVE.

Application filed March 16, 1925. Serial No. 15,860.

' trolling the air outlet may be actuated by differences cttemperature or pressure within the heating system or the valve casing, or by the buoyancy of the float when suilicient condensate accumulates within the casing, to thereby maintain proper and etlicient working conditions within the heating system.

The invention will be understood by refer ence to the accompanying drawings in which Fig. 1 is a perspective view of one embodiment of the invention, partly broken away, and the casing raised from its seat in the base; Fig. 2 a transverse section on the plane of the line 22 of Fig. 1; Fig. 3 a sectional detail view of the air outlet port and a portion of the valve stem; Fig. 1 a central vertical section of another embodiment of my invention; Fig. 5 a horizontal section on the plane of the line 55 of Fig. 41; Fig. 6 a plan view of a modified form of base which may be used; Fig. 7 a longitudinal section on the plane of the line 7-7 of Fig. 6; and Fig. 8 is a perspective view of a detail of a part of Fig. 4. Similar reference numerals indicate similar parts in the several views.

Referring to Figs. 1, 2 and 3, the numeral 1 designates the base of the casing, here shown as rectangular in cross-section, and having ,t'ormed therewith, or secured thereto at one corner, a hollow extension or spud 2 exteriorly threaded at its outer end to permit the attachment of the valve to the side of a steam radiator in the usual way. The base is formed with a transverse lug or wall 3 having an opening therein in which is loosely seated one end of the siphon tube 1, the displacement or withdrawal of said tube from its support being prevented by a flange 5 on the end of the tube. The outside diameter of the tube 1 is less than the inside diameter of the spud 52, as illustrated in Figs. 1 and 7-, to provide a "free and open passage from the radiator around the tube for air, steam or water, as will be hereinafter described. The siphon tube is "freely rotatable in the entension 2 and in the lug or wall 3 so that when inserted through the opening in the radiator it will not interfere with the proper attachment of the valve.

Openings 6 are formed in diagonally opposite corners of the base 1 (see Fig. 2) over which openings are secured the lower ends of the legs of a Li tube 7. At its upper end the tube 7 istormed with a port 8 having a valve seat and opening into the interior of the casing so that air, forced by pressure through the system to the casing, is permitted to escape. This port is adapted to be closed by a movable member or valve 9 secured at its lower end to a bell-shaped float 10, open at its lower end. The valve stem and float are supported upon a thermostatic member having a vertical section 11 and two transverse or laterally extending arms 12 and 13. The upper arm 12 embraces the valve stem 9 beneath a collar 14- and the lower arm 13 extends beneath the float and restsloosely upon the lug or wall 3 otthe base. The thermostatic member should have the high co-eilicient material of the bi-metallic strip toward the inside so that when expanded by heat, it will be bowed with the convex side toward the center of the casing, thus causing the uppertransverse arm 12 to move toward the upper end of the casing, in a substantially axial direction, to thereby raise the float and its attachedvalve stem to close the outlet port 8. As shown in Figures 1 and 2 the casing 15 is polygonal in'cross section. The float 10 being cylindrical in section and: slightly less in diameter than the distance between the flat sides of the easing, said sides serve as guidesto direct the vertical movements of the float. The corners of the casing form a series of vertical channels about the float and in one of said channels is located the vertical member 11 ot the thermostat. Because of the bowing or curving of the vertical section of the thermostatic member it is obvious that such movement will cause the transverse arms of said member to assume aradial position, the extent of the movement 01 the ends of the transverse arms farthest from the vertical strips being multiplied proportionally to their length.

The U tube, the float and its attached valve stem, and the thermostatic member, above described, are enclosed within the upper part 15 ofthe casing which issecured to the base in any suitable manner thus completely surrounding the enclosed parts. For purposes oi illustration, the upper part of. the casing is shown'raised from its normal position.

Assuming the valve above described to be attached to a radiator, with atmospheric temperature and pressure within the heating system and easing, the operation is as follows. The port 8 being open, as the steam or vapor pressure rises in the system the air contained within the radiator will be forced through the siphon tube e and the passageway provided in the spud 2, into the interior of the casing, thence through the port 8, downward through the legs of the U tube 7 and openings 6 to atmosphere. The air within the radiator and easing having been expelled and the latter now filled with steam, the thermostatic member will be heated and as it expands and is bowed inwardly, the upper arm 12 thereof, which operatively engages the valve stem 9 through the collar 14. will raise the float 10 and its attached valve stem to seat the valve and close the outlet port, and such port will remain closed until the ten'iperature within the casing falls to a degree which will cause a contraction of the thermostatic member and thus lower the arm 13 and permit the float and valve stem to fall sufficiently to open the port 8. This will allow of the escape of any accumulated air carried in by the steam or vapor. The port 8 will again be closed as soon as the ten'iperature within the casing rises to a degree to expand the thermostatic member to effect the seating of the valve.

So far, I have described only the action of the thermostat in seating or opening the valve. The float itself, however, functions not only as a carrier for the valve stem but if, for any cause, suflicient condensate accumulates within the casing, the float will rise by reason of its buoyancy and seat the valve in the outlet port independently of the action of the thermostat, thus preventing the escape of water through the port. This may occur when the temperature within the easing falls to such a degree as would effect the opening of the valve due to the contraction of the thermostatic member. Should the outlet port 8 be closed by the rising of the float independently of the action of the thermostatic member, the pressure within the radiator and easing will be equalized and the water within the casing will flow by gravity through the siphon tube 4 to the radiator and return to the boiler through the supply pipe, thus breaking the water seal and again opening the valve to permit the escape of any accumulated air. It will be noted in the construction shown that the inner end of the siphon tube' is prevented from rising so that a clear space is provided between such tube and the interior wall of the extension 2 to permit the entrance of air into the casing to break the water seal.

In the description of Fig. 1, I have considered the base 1 and the pyramidal part 15 as constituting the casing. In that form, the air outlet port and valve seat are in the U tube and the air escapes from such tube to the atmosphere through openings 6 in the base. In the embodiment of the invention illustrated in Fig. 4 the port for the escape of air is in the upper part of the casing and in addition to a thermostatic member and float to effect the movements of the valve stem under varying conditions of heat and the presence of condensate within the casing, I provide an additional means in the way of a diaphragm, operative under a pressure dilferential, to seat the valve.

In this form the base 16 of the casing circular in section and is formed with a spud 17 exteriorly screw-threaded to permit the attachment of the valve to a radiator. The siphon tube 18 is the same as that illustrated in Fig. 1, and is supported in an openin in a wall 18 extending from side to side of the base. The open end of the base is closed by a cap 19 formed with a projecting collar 20 between which and a shoulder formed on the base is clamped a diaphragm 21 preferably of thin sheet metal. This diaphragm is open to the atmosphere on its under side through openings 19 and the cap is formed with an upwardly extending stud 19 to limit the downward movement of the diaphragm. Upon the diaphragm is supported a saddle 22 (see Fig. 8) having aligned openings 23 in its legs through which openings the inner end of the siphon tube 18 passes. The openings 23 are GlOE'lgZllQtl vertically to permit the saddle to rise and fall with the movements of the diaphragm 21. Resting upon the saddle 22 is the lower transverse arm of thermostatic member the upper transverse arm of which bears against the inner surface of the upper wall of a float 25. On the upper end of the float is mounted a valve 26 adapted to be seated in the port 27 in the casing 28. The latter is secured to the base 16 so as to completely enclose the float and thermostatic member. It will thus be seen that the diaphragm supports the thermostatic member 24:, the float 25 and valve 26 and that the latter is adapted to be moved by differences of temperature or pressure, or by the rising of the float due to its buoyancy in the condensate if present in sufiicient amount.

Assuming atmospheric pressure throughout the system, the outlet port 27, in Fig. 4, will be open and the diaphragm 21 in its lowermost position. Upon increase of pressure and of temi ierature within the valve casing, the air will be forced out through port 27 and the valve seated by the expansion of the thermostatic member 24, the same as described in connection with Fig. 1. So long as the temperature within the casing is maintained to seat the valve 26 in the outlet port, the diaphragm 21 will remain in its lowermost position. As soon, however, as the pressure is reduced to a point where there is insufiicient steamor vapor to fill all of the radiator, the temperature in that part of the radiator will drop, thus effecting condensation of the steam and forming a partial vacuum. WVhen this occurs, atmospheric pressure acting through the openings 19 upon the under side of the diaphragm 21 will force the diaphragm upward, absorbing the normal contraction of-the thermostatic member and retaining the valve on its seat and holding it seated so long as the internal pressure of the system is less than atmospheric pressure. There is a lag in the action of the thermostat so that when the pressure has been removed and the temperature is falling the thermostat will not act to open the valve until sufficient time has elapsed for a considerable pressure differential to have been developedbetwe'en the inside of the system and atmosphere thus allowing ample time for the valve to be closed by the diaphragm. This will prevent any backflow of air into the system through the port 27. In other words, the diaphragm 21 acts to keep the valve seated whenever a partial vacuum is created within the casing so as to maintain a lowered pressure within the radiator and thus facilitate the re-entr y of steam into the radiators. A slight pressure will fill all of the radiators for the reason that, there being substantially no air to be expelled, there is little or no resistance to overcome.

The diaphragm 21 may be so constructed and arranged that it will normally hold the valve 26 seated so that the valve will be opened only when there is pressure in thecasing above atmosphere. Or the parts may be so constructed and arranged that the valve will be normally open and the dia phragm adapted to close it, or to absorb the contraction of the thermostatic member when the latter in such contraction holds the valve closed until the condensation in the radiator has produced a pressure differential sufficient to operate the diaphragm. I prefer the first arrangement as it produces the highest obtainable degree of vacuum in the heating system. In such case so long as there is no pressure in the heating system, the valve would seat in the outlet port, but as soon as the pressure is built up to two or three ounces, the diaphragm would be depressed, the valve opened and the accumulated air permitted to escape. The diaphragm would then remain in the open position until pres sure was again off the system. The advantage of this vacuum feature is that the radiators will fill with steam as soon as the steam is generated faster than it will be con densed by the cold surfaces of the radiators.

It will be further noted that the dia phragm acts to raise and lower the bottom support of the thermostatic member so that as the internal temperature drops and the thermostatic member beings to contract, the

diaphragm by the pressure, of the atmosphereonits, under side, or by its own resilience plus the pressure of the atmosphere, absorbs this contraction of the thermostatic member and holds the valve firmly on its seat exactly as the thermostatic member does when acting alone.

In Figs. 6 and 7 Ihave shown a form of base which may be used in the valve of Fig. 4 when the diaphragm is omitted. In such case, where the thermostatic member is lo-.

cated within the float. instead of, outside thereof, as In Fig. 1, the lower transverse arm of such memberwill rest upon the base.

In the foregoing description, and in the claims, it is to be understood'tl at the valve for closing the outlet port may be seated directly inv said port, asin Fig. t,.or in a tube leading to the outlet, as inv Fig. l. The expression a casing having an outlet port for the escape of air is intended to cover both constructions.

What I claim is 1. An air valve comprising a casing hav-' ing an outlet port, a valve for closing said port, and a thermostat comprising a substantially straight bimetallic strip and two transverse arms integral therewith located one at or near each end of said bimetallic strip for actuating said valve when subjected to varying temperatures.

2. Anair valve comprising a casing having an outlet port, a float, a valve mounted on said float and adapted to close said port, a thermostat composed of a substantially straight bimetallic strip and two transverse arms integral therewith, one of said arms engaging the base of said casing below said float and the other operatively engaging said valve above said float.

3. In a thermostatic air valve the combination of a longitudinally operating valve and a longitudinally disposed thermostatic member foroperating said valve, said member comprising a substantially straight bimetallic strip and two transverse arms integral therewith, one at or near each end thereof.

4. An air valve comprising a casing, an axially operating valve therein and a thermostatic member composed of a substantially straight bimetallic strip disposed at one side of the axis of said casing and having a transversearm thereon for actuating said valve by the expansion and contraction of said bimetallic strip.

5. An air valve comprising a casing, an axially movable valve therein, a thermostat composed of a substantially straight bimetallic strip constructed to have a movement transverse to said axis when subjected to varying temperatures, and means integral with said strip for changing said transverse movement to a substantially axial movement.

6. An air valve comprising a casing, an axially operating valve therein, a thermostatic member having a transverse movement relative to the travel of the valve When subjected to varying temperatures, and means integral With said member-for converting said transverse movementto a substantially axial and multiplied movement.

7. An air valve comprising a casing, an axially operating valve therein, a thermostatic member having a transverse movement when subjected to varying temperatures, and means constructed integral with said member for changing said transverse move ment to an axial movement.

8. An air valve comprising a cylindrical float, an angular casing enclosing said float the flat sides of which act as guides to direct the vertical movement, and the corners form a series of vertical channels about said float, and a thermostat having a transverse arm integral therewith and mounted in one of said channels, said transverse arm operatively engaging said float.

9. An air valve comprising an angular casing, a cylindrical float therein, the flat sides of said casing forming guides to control the axial movement of said float and the corners forming vertical channels adjacent thereto, a thermostatic member disposed in one of said channels, an axially operating valve and means for operating said valve by the expansion and contraction of said thermostat.

In Witness whereof I have hereunto signed my name this 12th day of March, 1925.

MOSES G. HUBBARD, 

